Fig. 1: NCOG sampling and the physical environment of the Southern California Current region.

a The number of samples collected at each CalCOFI station from 2014–2020. Stations highlighted by squares are the Cardinal Stations (sampled every cruise) (b), location of all samples by distance to coast (X axis) and depth (Y axis) (c), mean nitracline depth (m) measured at each station across all seven years. d Mean SST (°C) from NOAA’s OI SST V2 Dataset. White open circles represent the location of CalCOFI stations (e), overlap between NCOG 18Sv9 ASVs with those present in Tara Oceans and Tara Polar.